A practical reference on GABA-A receptor: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2025-08-23 and is reviewed periodically as new material appears.
Proposed mechanisms centre on the GABAergic system. Animal and tissue studies report changes in GABA-A receptor expression and reduced activity of GABA transaminase, the enzyme that degrades GABA. Effects on monoamine turnover, including serotonin and dopamine pathways, are also described, and a separate line of work links the peptide to increased expression of brain-derived neurotrophic factor in hippocampal tissue. Most of these findings come from rodent models and cell preparations. How the individual observations combine into a single coherent mode of action is not settled.
Pharmacokinetic data are sparse and largely derived from animal work. After intranasal administration the peptide appears in plasma within minutes, and reported half-lives are short, on the order of minutes to tens of minutes. Degradation proceeds through ordinary proteolytic cleavage into constituent amino acids and smaller fragments. Direct evidence that intact Selank reaches brain tissue in meaningful amounts is limited, and the extent of blood-brain barrier penetration is debated. Some authors argue that fragments, not the parent peptide, carry much of the observed activity.
Identity and purity of selank are established with reversed-phase high-performance liquid chromatography coupled to mass spectrometry. The peptide elutes from C18 columns with acetonitrile gradients in water containing trifluoroacetic acid or formic acid, and detection is usually performed by ultraviolet absorbance near 214 nm. Electrospray ionization in positive mode gives a doubly protonated ion near m/z 377, consistent with a mass of about 752 Da. Amino acid analysis or tandem mass spectrometry of fragment ions confirms the sequence. Because the molecule has no aromatic residues, it lacks a usable 280 nm chromophore, so low-wavelength detection or mass spectrometry is required.
Peptide bonds in selank are susceptible to hydrolysis under strongly acidic or basic conditions, and the terminal proline residues are vulnerable to exopeptidase activity in biological samples. Lyophilized powder stored dry at -20 °C typically remains stable for extended periods, whereas aqueous solutions degrade faster and may lose measurable purity within days to weeks depending on pH, temperature, and microbial load. Repeated freeze-thaw cycles promote aggregation and adsorption to container surfaces. For analytical work, solutions are usually prepared fresh, kept cold, and used within a single working day.
| Property | Value | Notes |
|---|---|---|
| Primary route studied | Intranasal | Also examined parenterally in animal work |
| Reported plasma half-life | Minutes to tens of minutes | Values vary widely between reports |
| Main model systems | Rodent behavioural and cell assays | Human trials are few and small |
| Principal proposed targets | GABA-A receptor, GABA transaminase | Monoamine and neurotrophic pathways also reported |
| Evidence grade | Preliminary | Limited independent replication |
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. It was designed as a stabilized analogue of tuftsin, a naturally occurring tetrapeptide fragment derived from the immunoglobulin heavy chain. The additional Pro-Gly-Pro segment at the carboxyl terminus is intended to slow enzymatic cleavage. The compound is usually described in the literature as a synthetic peptide with anxiolytic and cognitive-related activity, a label that reflects a research context rather than an approved therapeutic category.
Most published work on selank originates from a small number of research groups in the Russian Federation. A large share of that record appears in Russian-language journals, which limits access for readers who rely on English-indexed databases. Independent replication by laboratories outside the original research network is sparse in publicly available sources. This concentration of origin and language is a frequently noted feature when the compound is summarized in broader reviews of synthetic peptides.
Development work on the compound began in the 1980s and 1990s at the Institute of Molecular Genetics in Moscow, within the same research programme that produced the peptide Semax. Early investigators sought a tuftsin derivative with improved resistance to enzymatic breakdown and with activity in the central nervous system after peripheral administration. Most of the primary literature from this period was published in Russian, a factor that still shapes how easily the findings can be checked by outside groups.
Naming for this compound is not fully standardised in English sources. The spelling Selanc appears in some transliterations, and catalogue entries may instead list the peptide sequence itself as the identifier. Reference material sometimes groups it with other short synthetic peptides studied for behavioural effects, which can create confusion when citations are compared. Distinguishing the exact sequence from related tuftsin analogues is therefore a practical first step when reviewing any dataset or specification sheet.
== Military == In a military context, the term materiel refers either to the specific needs (excluding manpower) of a force to complete a specific mission, or the general sense of the needs (excluding manpower) of a functioning army. An important category of materiel is commonly referred to as ordnance, especially concerning mounted guns (artillery) and the shells they consume. Along with fuel, and munitions in general, the steady supply of ordnance is an ongoing logistical challenge in active combat zones. Materiel management consists of continuing actions relating to planning, organizing, directing, coordinating, controlling, and evaluating the application of resources to ensure the effective and economical support of military forces. It includes provisioning, cataloging, requirements determination, acquisition, distribution, maintenance, and disposal. The terms "materiel management", "materiel control", "inventory control", "inventory management", and "supply management" are synonymous. Materiel is often shipped to and used in severe climates without controlled warehouses or fixed material-handling equipment. Packaging and labeling often need to meet stringent technical specifications to help ensure proper delivery and final use. Some military procurement allows for commercial packaging rather than the more stringent military grades.
== Economic inequality == In Credit Suisse's Global Wealth Databook 2018, Thailand overtook Russia and India to claim the title of the world's most economically unequal nation. The top 10 percent of Thailand's population as measured by wealth control 85.7 percent of the nation's riches. The bottom 70 percent control five percent. Thailand's Gini coefficient stood at 90.2 (100 = one person owns everything; 0 = total economic equality). Thailand's National Economic and Social Development Board (NESDB) was quick to repudiate the findings, calling them based on old data and faulty estimates. Thailand has been ranked the world's third most unequal nation after Russia and India, with a widening gap between rich and poor according to Oxfam in 2016. Global Wealth Report 2016: Credit Suisse's annual report on worldwide wealth and its distribution reported that Thailand ranked number three of 38 nations (1=most concentrated wealth; 38=least concentrated wealth) in the amount of national wealth owned by the top one percent. In Thailand, 58 percent of the nation's wealth was controlled by one percent of the population. The top 10 percent control almost 80 percent of the nation's wealth. Russia, at 74.5 percent, outdistanced all other nations in inequality. India at 58.4 percent nudged out Thailand for the second spot. Other ASEAN nations in the study were Indonesia at 49.3 percent and Singapore at 33 percent.
Chromosome studies are used in the general genetics clinic to determine a cause for developmental delay or intellectual disability, birth defects, dysmorphic features, or autism. Chromosome analysis is also performed in the prenatal setting to determine whether a fetus is affected with aneuploidy or other chromosome rearrangements. Finally, chromosome abnormalities are often detected in cancer samples. A large number of different methods have been developed for chromosome analysis:
Sources: en.wikipedia.org
== Pathophysiological implications == In several populations, SPINA-GBeta correlated with the area under the glucose curve and 2-hour concentrations of glucose, insulin and proinsulin in oral glucose tolerance testing, concentrations of free fatty acids, ghrelin and adiponectin, and the HbA1c fraction. SPINA-GBeta declines with increasing adherence to mediterranean diet, which has been explained with a reduction in the chronic stimulus for dynamical compensation, i.e. insulin hypersecretion. In hidradenitis suppurativa, an inflammatory skin disease, SPINA-GBeta is increased to compensate for reduced insulin sensitivity. This dynamical compensation is insufficient, however, in a subset of affected patients, resulting in a reduced static disposition index (SPINA-DI) and the onset of diabetes mellitus. Since SPINA-GBeta has higher predictive power than HOMA-Beta, its use has been suggested as a calculated early biomarker for the evolution and pathophysiology of gestational diabetes.
Periodontal pathology, also termed gum diseases or periodontal diseases, are diseases involving the periodontium (the tooth supporting structures, i.e. the gums). The periodontium is composed of alveolar bone, periodontal ligament, cementum and gingiva.
== Early life == Darren Burke was born in Halifax, Nova Scotia. He completed an undergraduate degree in Physical Education and a master's degree in Science from Dalhousie University. He was awarded a PhD in Exercise Physiology at the University of Saskatchewan in 2001 with the thesis "Individual creatine pool size and responsiveness associated with creatine supplementation".
Sources: en.wikipedia.org
31 December – Senior Conservatives, including Shadow Home Secretary Chris Philp, have criticised the awarding of a knighthood to Mayor of London Sadiq Khan, describing it as a "reward for failure". The National Archives releases three volumes of 10 Downing Street visitors' books signed by world figures, the first time these have been released. The books cover the years 1970 to 2003. Newly released government files reveal that Tony Blair was urged by senior ministers, including Jack Straw and John Prescott, to delay granting employment rights to citizens from Eastern and Central Europe when the EU expanded in 2004. Darryl Wilson, a councillor of Causeway Coast and Glens Borough Council, resigns from the Ulster Unionist Party following a controversy over the selection for an Assembly seat, and will continue as an independent.
The word "aptamer" is a neologism coined by Andrew D. Ellington and Jack Szostak in their first publication on the topic. They did not provide a precise definition, stating "We have termed these individual RNA sequences 'aptamers', from the Latin aptus, to fit." The word itself, however, derives from the Greek word ἅπτω, to connect or fit (as used by Homer (c. 8th century BC)) and μέρος, a component of something larger. A typical aptamer is a synthetically generated ligand exploiting the combinatorial diversity of DNA, RNA, XNA, or peptide to achieve strong, specific binding for a particular target molecule or family of target molecules. Aptamers are occasionally classified as "chemical antibodies" or "antibody mimics". However, most aptamers are small, with a molecular weight of 6-30 kDa, in contrast to the 150 kDa size of antibodies, and contain one binding site rather than the two matching antigen binding regions of a typical antibody.
Hypoprolactinemia, or serum prolactin deficiency, is associated with ovarian dysfunction in women, and arteriogenic erectile dysfunction, premature ejaculation, oligozoospermia, asthenospermia, hypofunction of seminal vesicles and hypoandrogenism in men. In one study, normal sperm characteristics were restored when prolactin levels were raised to normal values in hypoprolactinemic men. Hypoprolactinemia can result from hypopituitarism, excessive dopaminergic action in the tuberoinfundibular pathway and ingestion of D2 receptor agonists such as bromocriptine. Dextroamphetamine has been shown to reduce serum prolactin, presumably due to its dopaminergic effects, indirectly increasing activation of dopamine D2 receptors with data showing intravenous dextroamphetamine at doses between 7.5 mg to 15 mg reducing serum prolactin by 27-32% and 30-37%, respectively, while an oral dose of 20 mg led to a sustained 40% reduction of serum prolactin in postpartum women.
Currently, no over-the-counter weight-loss supplements have met criteria for recommended use by physicians. Dexatrim claims to provide a powerful benefit for weight loss despite the lack of scientific data to support their claims. Dexatrim further provides a disclaimer that no claims of efficacy and safety made by Dexatrim have been approved by the FDA. Although available OTC, the active ingredients in Dexatrim products carry risk of side effects, adverse reactions and adverse drug interactions, particularly if used at high-recommended or higher-than-recommended doses and/or for prolonged periods. The Dexatrim product itself carries a warning about the possible side effects of Dexatrim in patients with a history of high blood pressure, and also recommends the advice of a qualified physician before taking Dexatrim. In addition, the use of Dexatrim or other OTC weight-loss supplements presents a possible factor in establishing disruptive eating patterns, increases the risk that individuals will use these OTC supplements in lieu of seeking proper medical and nutritional consultation, and presents increased psychological risks associated with unsuccessful weight-loss attempts.
Sources: en.wikipedia.org
Reports describe modulation of GABA signalling, changes in monoamine turnover and effects on neurotrophic factor expression. These observations come mainly from animal and cell studies. A single unifying mechanism has not been demonstrated.
The peptide enters plasma rapidly and is broken down by ordinary proteases into amino acids and shorter fragments. Reported half-lives are short. Whether meaningful amounts of the intact molecule reach the brain is an open question.
Most clinical reports are small, published in Russian and not independently replicated. English-language reviews highlight the absence of large randomised trials. Conclusions about efficacy should be treated as provisional.
Identity is confirmed by matching the retention time in reversed-phase chromatography against a reference standard and by measuring the molecular mass with mass spectrometry. Tandem mass spectrometry or amino acid analysis can verify the sequence of the seven residues. Because the peptide contains no aromatic amino acids, detection at 280 nm is not useful.